Closed circulation system for centrifugal mother liquor in perchlorate production process

Abstract

The invention discloses a closed-loop circulation system for centrifugal mother liquor in a perchlorate production process. The closed-loop circulation system comprises a crystallizer, a centrifugal head tank, a centrifugal machine, a mother liquor intermediate tank, a cyclone hydraulic separator, a mother liquor storage tank, a mother liquor mixing tank and a plurality of material conveying pipelines. Crystal mush discharged from the crystallizer sequentially enters the centrifugal head tank and the centrifugal machine to realize solid-liquid separation, mother liquor discharged from a liquid phase of the centrifugal machine is temporarily stored in the mother liquor middle tank and then is subjected to secondary solid-liquid separation by the cyclone hydraulic separator, and clear liquor used for reflowing a front-end refining section and mixed liquor used for returning to a crystallization section are obtained. And the mixed liquid is mixed with sodium perchlorate electrolyte from an electrolysis section in the mother liquid mixing tank and then conveyed back to the crystallizer by a crystallizer feeding pump. By means of the structure, soluble sodium perchlorate can be recycled, insoluble impurities are discharged at the crystallization section, full-amount closed-loop circulation of centrifugal mother liquor is achieved, the impurities are prevented from entering a refining section, and the operation stability of the system is improved.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, and in particular to a closed-loop circulation system for centrifuged mother liquor in a perchlorate production process. Background Technology

[0002] Currently, in sodium chlorate electrolysis, the concentration of the electrolyte is a crucial factor affecting electrolysis efficiency and the quality of the electrolysis products. Traditional methods for controlling electrolyte concentration typically rely on one-time dilution or overflow discharge. These methods not only struggle to precisely control concentration changes but also tend to lead to low electrolysis efficiency and high energy consumption.

[0003] Therefore, how to improve electrolysis efficiency and reduce energy consumption through precise concentration adjustment has always been a technical challenge in the field of sodium chlorate electrolysis. To address this, this invention proposes a chlorate electrolyte concentration control device and its application method based on an electrolyte circulation tank, aiming to optimize the electrolysis process by precisely adjusting the concentration through a multi-stage electrolyte circulation tank. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides the following technical solution: A closed-loop circulation system for centrifuged mother liquor in a perchlorate production process includes a crystallizer, a crystallizer discharge pump, a centrifugal high-level tank, a centrifuge, a mother liquor intermediate tank, a hydrocyclone pump, a hydrocyclone separator, a mother liquor storage tank, a mother liquor mixing tank, an electrolyte storage tank, and a crystallizer feed pump. The material outlet of the crystallizer is connected to the centrifugal high-level tank via a crystallizer discharge pump. The outlet of the centrifugal high-level tank is connected to the inlet of the centrifuge. The solid phase outlet of the centrifuge is connected to the packaging section, and the liquid phase outlet of the centrifuge is connected to the liquid inlet of the mother liquor intermediate tank. The outlet of the mother liquor intermediate tank is connected to a hydrocyclone separator via a hydrocyclone pump. The hydrocyclone separator has a clear liquid outlet and a mixed liquid outlet. The clear liquid outlet is connected to the mother liquor storage tank via a pipeline, and the outlet of the mother liquor storage tank is connected to the refining section. The mixed liquid outlet of the hydrocyclone separator is connected to the mother liquor mixing tank via a pipeline. The mother liquor mixing tank has a process liquid replenishment port. The outlet of the mother liquor mixing tank is connected to the material inlet of the crystallizer via a crystallizer feed pump, so that the mixed liquid can be mixed with the process liquid and then re-enter the crystallizer.

[0005] Furthermore, the process liquid is a sodium perchlorate electrolyte from the electrolysis section.

[0006] Furthermore, the process liquid replenishment port of the mother liquor mixing tank is connected to the electrolyte storage tank.

[0007] Furthermore, the mother liquor mixing tank is equipped with a stirring device.

[0008] Furthermore, the centrifuge high-level tank is provided with an overflow port, which is connected to the mother liquor intermediate tank through a pipeline.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a dual-path closed-loop circulation structure for the centrifuged mother liquor, separating the clarified liquid from the impurities, to achieve differentiated utilization of the components with different properties. The clarified liquid obtained from the hydrocyclone is directionally transported to the upstream refining section, avoiding product loss due to soluble sodium perchlorate being discharged with the mother liquor and allowing the clarified liquid to re-enter the upstream process, thus improving raw material utilization. The impurities discharged from the hydrocyclone are mixed with the sodium perchlorate electrolyte from the electrolysis section in the mother liquor mixing tank and then returned to the crystallizer. This allows impurities to accumulate in the crystallization section and be discharged with the solid phase, preventing them from entering the refining section and causing system contamination. This effectively reduces the risk of impurity accumulation in the system and improves the operational stability of the entire production system.

[0010] Furthermore, by adding sodium perchlorate electrolyte to the mother liquor mixing tank and using a mixing tank stirring device, this invention ensures that the impurity liquid has suitable concentration, viscosity, and flowability before returning to the crystallizer. This avoids problems such as localized oversaturation of the crystallizer, uncontrolled crystallization, and pipeline blockage caused by fluctuations in the composition of the impurity liquid, thereby improving the feeding conditions of the crystallizer and enhancing the continuity and controllability of the crystallization operation. Through the above structural combination, this invention achieves full recycling of the centrifugal mother liquor without the need for discharge. While increasing the perchlorate yield, it reduces system material loss and environmental risks, demonstrating significant economic benefits and engineering application value. Attached Figure Description

[0011] Figure 1 This is a process flow diagram of an embodiment of the present invention.

[0012] Among them, 1. Crystallizer; 2. Crystallizer discharge pump; 3. Centrifugal high-level tank; 4. Centrifuge; 5. Packaging equipment; 6. Centrifugal mother liquor intermediate tank; 7. Swirl pump; 8. Swirl separator; 9. Refining section; 10. Mother liquor mixing tank; 11. Electrolyte storage tank; 12. Crystallizer feed pump. Detailed Implementation

[0013] The technologies in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0014] Reference Figure 1This embodiment proposes a closed-loop circulation system for centrifugal mother liquor in a perchlorate production process, including a crystallizer 1, a crystallizer discharge pump 2, a centrifugal high-level tank 3, a centrifuge 4, packaging equipment 5, a centrifugal mother liquor intermediate tank 6, a hydrocyclone pump 7, a hydrocyclone separator 8, a refining section 9, a mother liquor mixing tank 10, an electrolyte storage tank 11, and a crystallizer feed pump 12. The crystallizer 1 is used to evaporate and crystallize materials from the upstream process to form a crystal slurry; the crystallizer discharge pump 2 is used to transport the crystal slurry from the crystallizer 1 to the centrifugal high-level tank 3; the centrifugal high-level tank 3 is used to temporarily store and stabilize the crystal slurry, allowing it to enter the centrifuge 4 in a stable state; the centrifuge 4 is used to perform solid-liquid separation of the crystal slurry to obtain wet crystals and centrifugal mother liquor, wherein the wet crystals are sent to the packaging equipment 5 for drying and packaging, and the centrifugal mother liquor enters the centrifugal mother liquor intermediate tank 6; the centrifugal mother liquor intermediate tank 6 is used to temporarily store and buffer fluctuations in the centrifugal discharge; the hydrocyclone pump 7 is used to transport the centrifugal mother liquor intermediate tank... The mother liquor in tank 6 is transported to hydrocyclone 8; hydrocyclone 8 is used to perform secondary solid-liquid separation on the mother liquor to obtain clear liquid and impurity liquid respectively, wherein the clear liquid is discharged to the refining section 9 via pipeline, and the impurity liquid is discharged to the mother liquor mixing tank 10 via pipeline; the mother liquor mixing tank 10 is also provided with a process liquid replenishment port for receiving process liquid and mixing it with the impurity liquid from hydrocyclone 8 to form a mixed solution suitable for crystallization in crystallizer 1; crystallizer feed pump 12 is used to transport the mixed solution in mother liquor mixing tank 10 to crystallizer 1, so that the mixed solution re-participates in the crystallization process.

[0015] Preferably, the process liquid is a sodium perchlorate electrolyte from the electrolysis section. This electrolyte contains a certain concentration of perchlorate ions and sodium ions, which is used to dilute and adjust the impurities in the hydrocyclone 8 so that the mixed solution meets the feeding requirements of the crystallizer 1.

[0016] Preferably, the process liquid replenishment port of the mother liquor mixing tank 10 is connected to the electrolyte storage tank 11, which is used to replenish sodium perchlorate electrolyte to the mother liquor mixing tank 10 to adjust the concentration and flowability of the impurity liquid.

[0017] Preferably, the mother liquor mixing tank 10 is equipped with a stirring device for mixing the impurities with the sodium perchlorate electrolyte to ensure a uniform composition of the mixed solution and prevent impurities from settling and local concentration unevenness from affecting the crystallization process.

[0018] Preferably, the centrifugal high-level tank 3 is provided with an overflow port, which is connected to the mother liquor intermediate tank 6 through an overflow pipe. This is used to automatically return the crystal slurry or mother liquor to the mother liquor intermediate tank 6 when the liquid level in the centrifugal high-level tank 3 exceeds the set height, so as to avoid the liquid level in the centrifugal high-level tank being too high.

[0019] With the arrangement shown in this embodiment, the clear liquid is directionally transported to the refining section 9 via the clear liquid branch to the hydrocyclone separator 8, while the impurities are mixed with the process liquid supplied by the electrolyte storage tank 11 in the mother liquor mixing tank 10 via the impurities branch and then returned to the crystallizer 1, thereby realizing the dual-path circulation transport of the centrifuged mother liquor.

[0020] In this embodiment, the sodium perchlorate slurry generated in the crystallizer 1 is transported to the centrifugal high-level tank 3 via the crystallizer discharge pump 2. After the liquid level is stabilized in the centrifugal high-level tank 3, it flows into the centrifuge 4 by gravity for solid-liquid separation. The wet crystals discharged from the solid phase outlet of the centrifuge 4 enter the packaging equipment 5 for drying and packaging to obtain the sodium perchlorate product. The centrifugal mother liquor discharged from the liquid phase outlet of the centrifuge 4 enters the mother liquor intermediate tank 6, which is used to temporarily store the centrifugal mother liquor and buffer fluctuations in the centrifugal discharge volume.

[0021] When the liquid level in the intermediate mother liquor tank 6 reaches the set value, the hydrocyclone pump 7 starts and transports the centrifuged mother liquor to the hydrocyclone separator 8 for solid-liquid separation, separating the fine crystals and insoluble impurities entrained in the centrifuged mother liquor. The clear liquid outlet of the hydrocyclone separator 8 is transported to the refining section 9 via pipeline, allowing the clear liquid to re-enter the front-end dissolution and refining operation to recover the dissolved components of sodium perchlorate; the impure mother liquor discharged from the impurity outlet of the hydrocyclone separator 8 enters the mother liquor mixing tank 10, where it is mixed with the process liquid from the electrolyte storage tank 11. The mixed solution is then transported back to the crystallizer 1 via the crystallizer feed pump 12, allowing the impurities to precipitate out with the crystals in the crystallization section and ultimately be discharged from the system.

[0022] Based on the above principle, a complete closed-loop circulation of the centrifuged mother liquor is achieved. Dissolved sodium perchlorate is preferentially returned to the refining section 9 for effective reuse, while insoluble impurities are removed through the crystallization section, thus forming a dual-path closed-loop circulation system with the clear liquid returning to the front end and the impurities returning to the crystallization section.

Claims

1. A closed loop system for recycling centrifuged mother liquor in a perchlorate production process, characterized in that, The system comprises a crystallizer, a crystallizer discharge pump, a centrifugal high tank, a centrifuge, a mother liquor intermediate tank, a hydrocyclone pump, a hydrocyclone separator, a mother liquor storage tank, a mother liquor mixing tank, an electrolyte storage tank and a crystallizer feed pump. The material outlet of the crystallizer is connected to the centrifugal high tank through the crystallizer discharge pump, the outlet of the centrifugal high tank is connected to the feed inlet of the centrifuge; the solid phase discharge outlet of the centrifuge is connected to the packaging section, the liquid phase discharge outlet of the centrifuge is connected to the liquid inlet of the mother liquor intermediate tank; the outlet of the mother liquor intermediate tank is connected to the hydrocyclone separator through the hydrocyclone pump, the hydrocyclone separator has a clear liquid discharge outlet and a mother liquor discharge outlet, wherein the clear liquid discharge outlet is connected to the mother liquor storage tank through a pipeline, and the outlet of the mother liquor storage tank is connected to the refining section; the mother liquor discharge outlet of the hydrocyclone separator is connected to the mother liquor mixing tank through a pipeline, the mother liquor mixing tank has a process liquid supplement inlet; the outlet of the mother liquor mixing tank is connected to the material inlet of the crystallizer through the crystallizer feed pump, so that the mother liquor can be mixed with the process liquid and then re-enter the crystallizer.

2. The closed loop system for recycling the centrifugation mother liquor in perchlorate production process according to claim 1, characterized in that, The process liquid is sodium perchlorate electrolyte from the electrolysis section.

3. The closed loop system for recycling the centrifugation mother liquor in perchlorate salt production process according to claim 2, characterized in that, The process liquid supplement inlet of the mother liquor mixing tank is connected to the electrolyte storage tank.

4. The closed loop system for recycling the centrifugation mother liquor in perchlorate salt production process according to claim 1, characterized in that, The mother liquor mixing tank is provided with a stirring device.

5. The closed loop system for recycling the centrifuged mother liquor in perchlorate salt production process according to claim 1, characterized in that, The centrifugal high tank is provided with an overflow port, which is connected to the mother liquor intermediate tank through a pipeline.

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